2004 CADILLAC XLR Owners Manual

A low tire warning light also appears on the instrument
panel cluster when a low tire condition exists. The
DIC message, CHECK TIRE PRESSURE and the low
tire pressure warning light will be shown each time
the engine is started and stay on until the low tire
condition is corrected.
When the tire pressure
monitoring system warning
light is lit, one or more
of your tires is signi®cantly
under-in¯ated.
You should stop and check your tires as soon as
possible, and in¯ate them to the proper pressure as
indicated on the vehicle's tire information placard.
Driving on a signi®cantly under-in¯ated tire causes the
tire to overheat and can lead to tire failure.
Under-in¯ation also reduces fuel efficiency and tire tread
life, and may affect the vehicle's handling and stopping
ability. Each tire, including the spare, should be
checked monthly when cold and set to the
recommended in¯ation pressure as speci®ed in the
vehicle placard and owner's manual.The Tire and Loading Information Label (tire information
placard) is either on the rear edge of the driver's door
or the driver's door jamb near the latch. This label shows
the size of your vehicle's original tires and the correct
in¯ation pressure for your vehicle's tires when they
are cold. See
In¯ation - Tire Pressure on page 5-57.
Your vehicle's TPM system can alert you about a low or
high tire pressure condition but it does not replace
normal tire maintenance. See
Tire Inspection and
Rotation on page 5-60
Each TPM sensor has a unique identi®cation code that
is matched to one of the four tire positions on your
vehicle. The tire and wheel assembly positions are, left
front (LF); right front (RF); right rear (RR) and left
rear (LR). Any time you rotate your vehicle's tires or
replace one or more TPM sensors, the identi®cation
codes will need to be matched to the new tire and wheel
position. The TPM matching process is performed in
a speci®c sequence and time limit. A special tool is also
required. See your dealer for service.
The SVC TIRE MONITOR message is displayed when
the TPM system is malfunctioning. For example,
one or more TPM sensors may be inoperable or
missing. See your dealer for service.
5-59

The TPM system operates on a radio frequency subject
to Federal Communications Commission (FCC) Rules
and with Industry and Science Canada.
This device complies with Part 15 of the FCC Rules and
with RSS-210 of Industry and Science Canada.
Operation is subject to the following two conditions:
(1) This device may not cause harmful interference, and
(2) this device must accept any interference received
including interference that may cause undesired
operation of the device.
Changes or modi®cations to this system by other than
an authorized service facility could void authorization to
use this equipment.Tire Inspection and Rotation
Your vehicle's tires should be inspected regularly for
wear. Any time you notice unusual wear, rotate
your tires as soon as possible and check wheel
alignment. Also check for damaged tires or wheels. See
When It Is Time for New Tires on page 5-62andWheel Replacement on page 5-66for additional
information.
When rotating your vehicle's tires, always use the
correct rotation pattern shown here.
5-60

After the tires have been rotated, adjust the front and
rear in¯ation pressures as shown on the tire and loading
information label, see
In¯ation - Tire Pressure on
page 5-57andLoading Your Vehicle on page 4-32.
Vehicles equipped with the Tire Pressure Monitor (TPM)
system will need to have the sensors reset after a tire
rotation is performed. A special tool is needed to
reset the sensor identi®cation codes. See your dealer
for service. Make certain that all wheel nuts are properly
tightened. See
Wheel Replacement on page 5-66and
ªWheel Nut Torqueº underCapacities and Speci®cations
on page 5-91.
{CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after a time. The wheel could
come off and cause a crash. When you change
a wheel, remove any rust or dirt from places
where the wheel attaches to the vehicle. In an
emergency, you can use a cloth or a paper
towel to do this; but be sure to use a scraper
or wire brush later, if you need to, to get all the
rust or dirt off.
5-61

When It Is Time for New Tires
One way to tell when it's
time for new tires is to
check the treadwear
indicators, which will
appear when your tires
have only 1/16 inch
(1.6 mm) or less of tread
remaining.You need a new tire if any of the following statements
are true:·You can see the indicators at three or more places
around the tire.
·You can see cord or fabric showing through the
tire's rubber.
·The tread or sidewall is cracked, cut or snagged
deep enough to show cord or fabric.
·The tire has a bump, bulge or split.
·The tire has a puncture, cut or other damage that
can't be repaired well because of the size or
location of the damage.
5-62

Buying New Tires
To ®nd out what kind and size of tires you need, look at
the Tire and Loading Information label. For information
about this label and where to ®nd it, see
Loading
Your Vehicle on page 4-32.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Speci®cation (TPC Spec)
number on each tire's sidewall. When you get new tires,
GM recommends that you get tires with that same
TPC Spec number. That way your vehicle will continue
to have tires that are designed to give proper
endurance, handling, speed rating, load range, traction,
ride, tire pressure monitoring system performance
and other things during normal service on your vehicle.
If your tires have an all-season tread design, the
TPC number will be followed by an ªMSº (for mud
and snow).
Whenever you replace your tires with those not having
a TPC Spec number, make sure they are the same
size, load range, speed rating and construction
type (bias, bias-belted or radial) as your original tires.
If you replace your vehicle's tires with those not having a
TPC Spec number, the tire pressure monitoring
system may give an inaccurate low-pressure warning.
Non-TPC Spec tires may give a low-pressure warning
that is higher or lower than the proper warning level you
would get with TPC Spec numbered tires.
{CAUTION:
Mixing tires could cause you to lose control
while driving. If you mix tires of different sizes
or types (radial and bias-belted tires), the
vehicle may not handle properly, and you
could have a crash. Using tires of different
sizes may also cause damage to your vehicle.
Be sure to use the same size and type tires on
all wheels.
{CAUTION:
If you use bias-ply tires on your vehicle, the
wheel rim ¯anges could develop cracks after
many miles of driving. A tire and/or wheel
could fail suddenly, causing a crash. Use only
radial-ply tires with the wheels on your vehicle.
5-63

Uniform Tire Quality Grading
Quality grades can be found where applicable on the
tire sidewall between tread shoulder and maximum
section width. For example:
Treadwear 200 Traction AA Temperature A
The following information relates to the system
developed by the United States National Highway
Traffic Safety Administration, which grades tires by
treadwear, traction and temperature performance. (This
applies only to vehicles sold in the United States.)
The grades are molded on the sidewalls of most
passenger car tires. The Uniform Tire Quality Grading
system does not apply to deep tread, winter-type
snow tires, space-saver or temporary use spare tires,
tires with nominal rim diameters of 10 to 12 inches
(25 to 30 cm), or to some limited-production tires.
While the tires available on General Motors passenger
cars and light trucks may vary with respect to these
grades, they must also conform to federal safety
requirements and additional General Motors Tire
Performance Criteria (TPC) standards.
Treadwear
The treadwear grade is a comparative rating based on
the wear rate of the tire when tested under controlled
conditions on a speci®ed government test course.
For example, a tire graded 150 would wear one and
a half (1.5) times as well on the government course as
a tire graded 100. The relative performance of tires
depends upon the actual conditions of their use,
however, and may depart signi®cantly from the norm
due to variations in driving habits, service practices and
differences in road characteristics and climate.
Traction ± AA, A, B, C
The traction grades, from highest to lowest, are AA, A,
B, and C. Those grades represent the tire's ability
to stop on wet pavement as measured under controlled
conditions on speci®ed government test surfaces of
asphalt and concrete. A tire marked C may have poor
traction performance. Warning: The traction grade
assigned to this tire is based on straight-ahead braking
traction tests, and does not include acceleration,
cornering, hydroplaning, or peak traction characteristics.
5-64

Temperature ± A, B, C
The temperature grades are A (the highest), B, and C,
representing the tire's resistance to the generation
of heat and its ability to dissipate heat when tested
under controlled conditions on a speci®ed indoor
laboratory test wheel. Sustained high temperature can
cause the material of the tire to degenerate and
reduce tire life, and excessive temperature can lead to
sudden tire failure. The grade C corresponds to a
level of performance which all passenger car tires must
meet under the Federal Motor Vehicle Safety Standard
No. 109. Grades B and A represent higher levels of
performance on the laboratory test wheel than the
minimum required by law.
Warning: The temperature grade for this tire is
established for a tire that is properly in¯ated and not
overloaded. Excessive speed, underin¯ation, or
excessive loading, either separately or in combination,
can cause heat buildup and possible tire failure.
Wheel Alignment and Tire Balance
The wheels on your vehicle were aligned and balanced
carefully at the factory to give you the longest tire life
and best overall performance.
Scheduled wheel alignment and wheel balancing are
not needed. However, if you notice unusual tire wear or
your vehicle pulling one way or the other, the alignment
may need to be reset. If you notice your vehicle
vibrating when driving on a smooth road, your wheels
may need to be rebalanced.
5-65

Wheel Replacement
Replace any wheel that is bent, cracked, or badly rusted
or corroded. If wheel nuts keep coming loose, the
wheel, wheel bolts and wheel nuts should be replaced.
If the wheel leaks air, replace it (except some
aluminum wheels, which can sometimes be repaired).
See your dealer if any of these conditions exist.
Your dealer will know the kind of wheel you need.
Each new wheel should have the same load-carrying
capacity, diameter, width, offset and be mounted
the same way as the one it replaces.
If you need to replace any of your wheels, wheel bolts
or wheel nuts, replace them only with new GM
original equipment parts. This way, you will be sure to
have the right wheel, wheel bolts and wheel nuts
for your vehicle.{CAUTION:
Using the wrong replacement wheels, wheel
bolts or wheel nuts on your vehicle can be
dangerous. It could affect the braking and
handling of your vehicle, make your tires lose
air and make you lose control. You could have
a collision in which you or others could be
injured. Always use the correct wheel, wheel
bolts and wheel nuts for replacement.
Notice:The wrong wheel can also cause problems
with bearing life, brake cooling, speedometer or
odometer calibration, headlamp aim, bumper height,
vehicle ground clearance and tire clearance to the
body and chassis.
5-66